A Novel Cryprosystem Based On An Enhanced Vigenere Algorithm Succeeded By A Randomized Partial Permutation

This document presents the development of a new innovative encryption method highly tailored to color images. This approach is built upon a significant enhancement of the conventional Vigenère method, leveraging two pseudo-random substitution tables and a novel replacement function operating at the pixel level. This function incorporates diffusion to effectively counter any attempted differential attacks. Following the initial encryption phase, the resulting vector is transformed into a matrix, followed by several permutations acting on all rows, controlled by a permutation matrix developed from pseudo-random vectors. Tests performed on a wide range of randomly chosen color images sourced from various databases, covering diverse formats and dimensions, have produced encouraging outcomes, validating our approach’s robustness of to known attacks.